From the Rolls-Royce experimental archive: a quarter of a million communications from Rolls-Royce, 1906 to 1960's. Documents from the Sir Henry Royce Memorial Foundation (SHRMF).
Page discussing and critiquing brake efficiency curves from a motoring journal.
| Identifier | ExFiles\Box 113\2\ scan0083 | |
| Date | 25th September 1924 | |
| R.R. 493A (50H) (D.B. 175 25-9-24) J.H.D. EXPERIMENTAL REPORT. -3- Expl. No. REF: Hs{Lord Ernest Hives - Chair}/Bal/LG23. 3.25. Graph: Y-axis: BRAKE EFFICIENCY DECN. FT/SEC2 X-axis: ROAD SPEED M.P.H. Underneath the curve in 'The Motor' the following sentence is found :- 'GRAPH SHOWING THE GOOD BRAKING FIGURES OBTAINED'. We cannot ourselves imagine a more inconsistent set of brakes than one whose efficiency varies in this manner, so that even were the curves correct, the remark of the journal is most misleading. Finally, a large number of the curves in 'The Motor' purport to give both the time and distance to rest from any road speed. On any normal car, once the brakes have been applied to obtain maximum effect, the retardation of the car is uniform unless the road surface varies enormously, say from concrete to wet macadam. If an inferior brake lining is employed, it is just possible that towards the end of a stop from 60 m.p.h., the brakes might lose some of their grip due to heat but most unlikely at the lower speeds. As all the tests we reproduce were carried out contd :- | ||